Managing Serviceguard A.11.20, March 2013

For information about configuring NTP services, refer to the HP-UX manual HP-UX Internet Services
Administrator’s Guide posted at http://www.hp.com/go/hpux-networking-docs.
Tuning Network and Kernel Parameters
Serviceguard and its extension products, such as SGeSAP and SGeRAC, have been tested with
default values of the network and kernel parameters supported by the ndd and kmtune utilities.
You may need to adjust these parameters for larger cluster configurations and applications.
• ndd is the network tuning utility. For more information, see the man page for ndd (1m)
• kmtune is the system tuning utility. For more information, see the man page for kmtune
(1m).
Make adjustments with care, and if you experience problems, return the parameters to their default
values.
NOTE: If you contact HP support regarding Serviceguard or networking, please be sure to mention
any parameters that have been changed from their defaults.
Serviceguard has also been tested with non-default values for these network parameters:
• ip6_nd_dad_solicit_count — This network parameter enables the Duplicate Address
Detection feature for IPv6 addresses. You can find more information l under “IPv6 Relocatable
Address and Duplicate Address Detection Feature” (page 387).
• tcp_keepalive_interval — This network parameter controls the length of time the node
will allow an unused network socket to exist before reclaiming its resources so they can be
reused.
The following requirements must be met:
◦ The maximum value for tcp_keepalive_interval is 7200000 (2 hours, the HP-UX
default value).
◦ The minimum value for tcp_keepalive_interval is 60000 (60 seconds).
◦ The tcp_keepalive_interval value must be set on a node before Serviceguard is
started on that node. This can be done by configuring the new
tcp_keepalive_interval in the /etc/rc.config.d/nddconf file, which will
automatically set any ndd parameters at system boot time.
◦ The tcp_keepalive_interval value must be the same for all nodes in the cluster.
• ip_strong_es_model — This network parameter controls support for the strong end-system
model, which prevents a system from acting as a router. For more information about this
model, see the HP-UX IPSec Version A.03.00 Administrator's Guide which you can find at
http://www.hp.com/go/hpux-security-docs —> HP-UX IPSec Software.
ip_strong_es_model is disabled (set to 0) by default. Setting it to 1 enables it.
CAUTION: HP supports enabling this parameter only if you are not using a cross-subnet
configuration (page 29). Otherwise, leave the parameter at its default setting (zero, meaning
disabled).
Enabling this parameter allows you to configure a default gateway for each physical IPv4
interface. These gateways allow a system to send an unbound packet through the interface
for the address to which the socket (or communication endpoint) is bound. If the socket (or
communication endpoint) is not bound to a specific address, the system sends the packet
through the interface on which the unbound packet was received.
This means that the packet source addresses (and therefore the interfaces on a multihomed
host) affect the selection of a gateway for outbound packets once ip_strong_es_model
176 Building an HA Cluster Configuration